Polyethylene, production volume

Polystyrene. Polystyrene (PS) film and sheet has the third largest production volume, behind only the polyethylenes and poly(vinyl chloride). 

High density polyethylene (HDPE) is defined by ASTM D1248-84 as a product of ethylene polymerisation with a density of 0.940 g/cm or higher. This range includes both homopolymers of ethylene and its copolymers with small amounts of a-olefins. The first commercial processes for HDPE manufacture were developed in the early 1950s and utilised a variety of transition-metal polymerisation catalysts based on molybdenum (1), chromium (2,3), and titanium (4). Commercial production of HDPE was started in 1956 in the United States by Phillips Petroleum Company and in Europe by Hoechst (5). HDPE is one of the largest volume commodity plastics produced in the world, with a worldwide capacity in 1994 of over 14 x 10 t/yr and a 32% share of the total polyethylene production. 

Countries produciug commodity LLDPE and their capacities, as well as production volumes of some U.S. companies, are Hsted iu Table 5. Iu most cases, an accurate estimate of the total LLDPE production capacity is compHcated by the fact that a large number of plants are used, iu turn, for the manufacture of either HDPE or LLDPE iu the same reactors. VLDPE and LLDPE resius with a uniform branching distribution were initially produced in the United States by Exxon Chemical Company and Dow Chemical Company. However, since several other companies around the world have also aimounced their entry into this market, the worldwide capacity of uniformly branched LLDPE resins in 1995 is expected to reach a million tons. Special grades of LLDPE resins with broad MWD are produced by Phillips Petroleum Co. under the trade name Low Density Linear Polyethylenes or LDLPE. 

Production, Storage, and Shipment. As noted above, AUco Chemical, Amoco Chemical, Mitsubishi Gas Chemical, and Hbls all produce either the acid or the anhydride using different production techniques. The relatively small production volumes of pyromellitic acid and dianhydride results in both storage and shipment in polyethylene-lined fiber dmms of 22—136-kg capacity. 

Propanediol (1,3PD) is also undergoing a transition from a small-volume specialty chemical into a commodity. The driving force is its application in poly (trimethylene terephthalate) (PTT), which is expected to partially replace polyethylene terephthalate) and polyamide because of its better performance, such as stretch recovery. The projected market volume of PTT under the trade-names CORTERRA (Shell) and Sorona 3GT (Dupont) is 1 Mt a-1 within a few years. In consequence, the production volume of 1,3PD is expected to expand from 55kta-1 in 1999 to 360 kt a-1 in the near future. 1,3PD used to be synthesized from acrolein by Degussa and from ethylene oxide by Shell (see Fig. 8.8) but a fermentative process is now joining the competition. 

About 50% of the present world-wide plastics production (>200 Mt/a) is based on polyethylene and polypropylene. When polystyrene is included, this percentage rises to 60%. With regard to their total production volumes, polyolefin materials thus are among the top 10 of all products generated in chemical industry. Major producers of polyethylene and polypropylene are shown, together with their production capacities, in Figure 4. 

Blown film extrusion is perhaps the most widely used extrusion technique, by production volume. Billions of pounds of polyethylene are processed annually by this method to make products such as grocery sacks and trash can liners. In a blown film system (Figure 14-30), the melt is generally extruded vertically upward through an annular die. The thin tube is filled with air as it travels up to a collapsing frame that flattens it before it enters the nip rollers, which pull the film away from the die. The flattened tube then travels over a series of idle rollers to a slitter,... 

A variety of foams can be produced from various types of polyethylenes and cross-linked systems having a very wide range of physical properties, and foams can be tailor-made to a specific application. Polypropylene has a higher thermostability than polyethylene. The production volume of polyolefin foams is not as high as that of polystyrene, polyurethane, or PVC foams. This is due to the higher cost of production and some technical difficulties in the production of polyolefin foams. The structural foam injection molding process, described previously for polystyrene, is also used for polyethylene and polypropylene structural foams (see Figure 2.61). 

In January 1957, DuPont filed for a patent, based on the finding that the incorporation of higher a-olefins in PE (US Patent 4076698 Arthur William Anderson, Gelu Stoeff Stamatoff—Filed 4 January 1957 published 28 February 1978 DuPont, for what we now call LLDPE) improved the product, but for DuPont, it appears that this ethylene copolymer was not really a very attractive venture compared to their other, high-margin proprietary products, like nylon. Although Du Pont of Canada introduced such a process in 1960, worldwide the products remained a small volume specialty until 1978, when Union Carbide announced their Unipol process, and actually coined the name linear low-density polyethylene (LLDPE). As we see later, since 1980, LLDPE has continued to increase its importance in the evolution of the portfolio of polyethylene products, likely to approach 1/3 of the total PE market by the end of this decade. 

Polyethylene and polypropylene, as generic classes of plastics, are by far the most dominant. Together they account for approximately 70% of the world plastics production of about 230 X 10 tons in 2010 (www.plasticeurope.org, accessed 22 June 2013). Their production volumes reflect their versatility as materials in multiple applications. 

About one-third of the industrial production volume is covered by polyethylene, a polymer which has been number one for decades, (which clearly exceeds the successes of modem rock stars). So, apparently, this is a very boring game is there any room left for creative polymer chemists. ... 

The phase transition from disordered states of polymer melt or solutions to ordered crystals is called crystallization-, while the opposite process is called melting. Nowadays, more than two thirds of the global product volumes of synthetic polymer materials are crystallizable, mainly constituted by those large species, such as high density polyethylene (HOPE), isotactic polypropylene (iPP), linear low density polyethylene (LLDPE), PET and Nylon. Natural polymers such as cellulose, starch, silks and chitins are also semi-crystalUne materials. The crystalline state of polymers provides the necessary mechanical strength to the materials, and thus in nature it not only props up the towering trees, but also protects fragile lives. Therefore, polymer crystallization is a physical process of phase transition with important practical relevance. It controls the assembly of ordered crystalline structures from polymer chains, which determines the basic physical properties of crystalline polymer materials. 

The U.S. production volume of the aromatic polyester, poly(ethylene terephtha-late) (PET), is comparable to that of low-density polyethylene or polystyrene. The... 

The main thermoplastic polymer types are actylic, cellulosic, ethylene vinyl acetate (EVA), polyethylene terephthalate (PET), polyamides (nylons), polyethylene (PE), polystyrene (PS), polyvinyl chloride (PVC), polycarbonate and polypropylene (PP). PET, PVC, HOPE, LDPE, PS and PP have a higher production volume and relatively low cost. The main thermosetting polymer types are aminoplastics, epoxies, phenolics (phenol formaldehyde), polyesters and silicones. These polymers have a wide range of applications and their features are very different. 

This 5 billion (USD) petrochemical plant will have an annual capacity of 1.5 million metric tons (3.3 billion pounds) of ethylene and will manufacture 1.0 million metric tons (2.2 billion pounds) of polyethylene. Note that ethylene capacity in a world-class complex usually exceeds the volume of polyethylene production. This excess ethylene capacity is either used to manufacture other ethylene-based chemicals at the same complex or is sold as a commodity chemical when access to a distribution pipeline is available. This plant will utilize ethane as the feedstock for ethylene, which has a cost advantage over ethylene plants that use oil-derived naphtha as feedstock. 

The polyolefins business accounts for approximately 63% of the global polymer production. Worldwide production volume of polyethylene is about 76 MMT (million metric tons), polypropylene is about 56 MMT. Diagram 2.1 represents polymer business worldwide. 

Polyolefins, and in particular polyethylene (PE) represent the largest production volume material in the world (Gedde and Mattozzi, 2004). This is due in large part to its wide range of material responses, structural simplicity, and ease of production. Because of this PE, its copolymers, and its many end-use products have made their way into every facet of daily life. 

Polyethylene terephthalate polyester is the leading man-made fiber in production volume and owes its popularity to its versatility alone or as a blended fiber in textile structures. When the term "polyester" is used, it refers to this generic type. It is used extensively in woven and knitted apparel, home furnishings, and industrial appl ications. Modification of the molecular structure of the fiber through texturizing and or chemical finishing extends its usefulness in various applications. Polyester is expected to surpass cotton as the major commodity fiber in the future. 

Ethylene is the most important intermediate in the chemical industry. The production volume was about 120 metric tonnes/year in 2007 and is expected to increase to approximately 180 metric tonnes/year by 2020 [1]. The main outlet for ethylene, roughly 60%, is used for polyethylene, followed by ethylene oxide, vinyl chloride and styrene. Ethylene oxide is a key material in the production of surfactants and detergents. It is mainly converted to ethylene glycol which ends up in, for example, polyethylene tereph-thalate and glycol ether solvents. Vinyl chloride and styrene are almost exclusively used to produce polyvinyl chloride and polystyrene, respectively. Ethylene is an intermediate for more than 50% of the polymer production volume. 

Dimerization in concentrated sulfuric acid occurs mainly with those alkenes that form tertiary carbocations In some cases reaction conditions can be developed that favor the formation of higher molecular weight polymers Because these reactions proceed by way of carbocation intermediates the process is referred to as cationic polymerization We made special mention m Section 5 1 of the enormous volume of ethylene and propene production in the petrochemical industry The accompanying box summarizes the principal uses of these alkenes Most of the ethylene is converted to polyethylene, a high molecular weight polymer of ethylene Polyethylene cannot be prepared by cationic polymerization but is the simplest example of a polymer that is produced on a large scale by free radical polymerization... 

Table 6 shows the sales estimates for principal film and sheet products for the year 1990 (14). Low density polyethylene films dominate the market in volume, followed by polystyrene and the vinyls. High density polyethylene, poly(ethylene terephthalate), and polypropylene are close in market share and complete the primary products. A number of specialty resins are used to produce 25,000—100,000 t of film or sheet, and then there are a large number of high priced, high performance materials that serve niche markets. The original clear film product, ceUophane, has faUen to about 25,000 t in the United States, with only one domestic producer. Table 7 Hsts some of the principal film and sheet material manufacturers in the United States.

There are three basic types of polyethylene foams of importance (/) extmded foams from low density polyethylene (LPDE) (2) foam products from high density polyethylene (HDPE) and (J) cross-linked polyethylene foams. Other polyolefin foams have an insignificant volume as compared to polyethylene foams and most of their uses are as resia extenders. 

Styrene—butadiene elastomers, emulsion and solution types combined, are reported to be the largest-volume synthetic mbber, with 28.7% of the world consumption of all synthetic mbber in 1994 (38). This percentage has decreased steadily since 1973 when SBR s market share was 57% (39). The decline has been attributed to the switch to radial tires (longer milage) and the growth of other synthetic polymers, such as polyethylene, polypropylene, polyester, and polystyrene. Since 1985, production of SBR has been flat (Table 3). 

DistHlation is then used to separate the hydrocarbons into different products, including Hquid fuels and waxes with melting points ranging from about 45—106°C. Currently the waxes are produced in large volumes in South Africa and Malaysia, with an estimated 12,000—14,000 t consumed in the United States in 1994. Uses are similar to those for polyethylene waxes, including hot-melt adhesives and additives for inks and coatings. 

Industrial ethanol is one of the largest-volume organic chemicals used in industrial and consumer products. The main uses for ethanol are as an intermediate in the production of other chemicals (Table 8) and as a solvent. As a solvent, ethanol is second only to water. Ethanol is a key raw material in the manufacture of dmgs, plastics, lacquers, poHshes, plasticizers, perfumes, and cosmetics. Around 1960, manufacture of ethanol was the top consumer of ethylene in the United States, but since 1965 it has rated below manufacture of ethylene oxide and polyethylene. 

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